Does the generalist badge algorithm consider the current set of tags for any question I've answered and received at least 15 score on, even if I retag the question?

If so, does that mean that I could cover off my last few tags by retagging some question with a bunch of top 40 tags that I haven't got yet?

In case that's not clear, imagine that I already have enough score on answers in 18 of the top 40 tags. I haven't yet received enough score on any answers to questions tagged beginner or subjective.

If I go find an answer of mine that has received at least 15 score and edit the tags to add beginner and subjective, will that trigger my generalist badge?

I imagine that in some cases, this scenario is appropriate, especially if the new tags fit the question. However, it seems open to abuse, particularly if the badge is not revoked after other users correct the tags on that question.

One final clarification: 15 score means 15 reputation gain on an answer, doesn't it? So two upvotes and two downvotes on an answer would still cover any top 40 tags on that question, right?

Obviously I am not privy to the inner workings of the algorithm, but I'd say it's unlikely that history is retained during badge calculations. I've seen numerous hints from Jeff et al that imply that only the state at the time a badge calculation is run is relevant.

So you could conceivably game the system in the way you suggest, and even hide your tracks (to most prying eyes) by deleting the tags after you got the badge.

I don't know that it's official or anything, but this question shows when you're going to get the generalist badge. According to that, score for a tag is all upvotes on answers to questions with that tag minus all downvotes. (Wiki questions excluded.)

Now that I understand score is different from reputation gain, I see it's more work than I thought to game this badge. Most answers (mine anyway) have fewer than fifteen votes, so you'd have to retag a bunch of questions.